George e



(No Model.)

G. E. BROWN.

N 369 4 POLISHING LAP.

, 3l. Patented Sept. 6, 1887.

04's U.. .u

.... ...wn vfig.

` wmf/7L...

WIM/8853:

. 9a/maf.

Unrrnn STATES PArnNr Orifice@ GEORGE E. BROWIN, OF MADISON, XVISOONSI.

POLISHING-LAP.

SPECIFICATION forming part of Letters Patent No. 369,431, dated September 6, 1887.

Application filed Oltobcr 4, 1886. Sci-inl No. 215,305` (No model.)

To @ZZ whom, t may concern:

Be it known that I, GEORGE BROWN, a citizen of the United States, residing at Madison, in the county of Dane and State of fisconsin, have invented certain new and useful Improvements in Fabrics for Polishing-Laps, and I do hereby declare the following to be a full, clear, and exact description of the invention, suoli as will enable others skilled in the art to wliichit appertains to make and use the same.

This invention has relation to laps for polishing-tools of the class intended for imparting highly-polished and even surfaces to glass and other articles-*such as, for example, lenses; and the object of the invention iste provide a lap having asurface that will receive, retain, and gradually pay out or deliver the polishing-powders and lubricants uniformly over its entire surface,so that it will greatly expedite the operation of polishing and impart a highly-iinished surface to the article subjected to its action.

W'it-h these general objects in view, the invention consists in certain features of construction, hereinafter specified, and particularly pointed ont in the claims.

Referring to the drawings, Figure lis a plan, portions being broken away, showing the several materials composing the lap. Fig, 2 is a lap constructed in accordance with my invention and cut into disk form. Fig. 3 is avertical section oit' a polishing-tool of a form adapted to polish a lens, and provided with my improved lap; and Fig. 4 is a sectional view ot' the corrugated ifoil.

Like letters of reference indicate like parts in all the iigures.

Herctofore the operation of grinding and polishing has been carried on by means of castiron tools having polishing-heads of brass, lead, Ster, and in some instances the head of the tool has been provided with felt and cloth, thereby forming a polishing-lap for the reception otrouge or other polishing-powders. By experience it has been found that considerable time is consumed before a properpolish is obtained, and that a variety of tools are necessary for holding different grades of powders. Previous to this the contour of the head of the tool necessarily conformed more exactly to the curvature or irregular surface of thcarticle to be polished. This, of course, required a great collection of tools of different sized and shaped heads. This objection is also overcome by my invention, and asingle tool, be the head tlat, concave, or convex, is made to conform within certain limits to and operate upon a surface of any shape whatever.

In order that a clear understanding of my invention may be had, I will proceed to describe the same in detail.

The essential element of my invention is the employment of malleable metal in sheet or foil form. This is out to conform to the outline of the polishing-head of the tool and secured thereon by what is known in the art as cement-for instance, pitch, rosin, beeswax, Sie., usually thinned with alcohol. In using a lap made of lead-foil I find that better results are obtained by interposing between the foil and tool-head a layer of some flexible materialsuch as, for instance, felt, leather, or cloth-and this more especially when an extremely high polish is desired. I r

have also discovered that in using a lap the outer surface of which is of foil, although goed results are secured, still when rouge or other polishingpowder is applied with a lu- Y bricant it is likely to form in lumps and not spread evenly over the entire surface of the lap. This prevents the entire surface of the lap from coniingin contact and operating upon the surface to be polished, and of course causes more time to be consumed in bringing the surface to the degree of polish desired. To obviate this, therefore, I corrugate the lead-foil or other polishing-surface, either by tine ribs crossing each other at regular or irregular angles or by concentric rings ar'- ranged to cross each other, or in any other design. Bythis meansthcpolishing-powderand lubricant will be evenly distributed over the lap and as evenly imparted to the surface of the article to be polished. Alap thus formed imparts an extremely high even tinish over the surface of the article, and a shorter time is required than heretofore by reason of the entire surface of the lap being always and uniformly in contact with the surface ofthe article.

Vhen it is desired to use a finer grade of polishing-powder, the foil is removed vand re` placed by another and the finer grade of powder applied, this operation being repeated as apply it to the surface of the article to be pol-v ished, either revolving the polisher or article,

as desired. In this manner the cement is made to conform to the surface of the article to be polished. The foil C is then placed in position upon the cement and the lap is formed which the cementB is spread and ready for use.

If desired, a layer of cloth, leather, or felt, D, may be interposed between the head of the tool and lthe cement. Especially is this advisable where an extremely fine and highly polished surface is required, because this gives a very delicate yielding action to the lap upon the article.

Where a forni of lap approaching a hemisphereis desired, it may be advisable to applyv the foil thereof in separate strips, whereby a smooth surface of the lap is secured and no wrinkles or ridges formed in the foil, which latter would be the case were a single sheet forced to the form mentioned.

It is apparent that I may provide a material from which laps of any desired form may be cut, and to give the necessary firmness to the material I attach thereto a cloth or other similar flexible backing, D, (see Fig. 1,) upon and upon which is laid the foil.

In Fig. 3 the foil C is represented as plain, while in the other gures of the drawings vit is represented as corrugated.

In Fig. 4 the cement B is placed upon the back of the corrugated coil, so as to ll the concavities of the corrugations, whereby the corrugations are strengthened to withstand the pressure to which the foil is subjected when in use. The corrugated foil having the concavities in its back thus filled may be mounted directly upon the tool-head or upon a textile backing, the increased quantity of cement B, as shown in Fig. 3, being principally for the purpose of adapting the lap for conformation to irregular surfaces to be polished, and also to secure the foil to the cloth or tool-head.

' Having described my invention and its operation, what Ielaim is l. A lap for {polishing-tools, comprising a rigid foundation, a layerof cloth, felt, or other flexible material, a layer of cement, and a superimposed layer of corrugated foil, substantially as specified.

2. Alap for polishing-tools, comprising a layer of cement conforming to the surface of the article to he polished, and a layer of corrugated foil, substantially as specified.

'3. As an article of manufacture, afabric for forming polishing-laps, which consists of a flexible backing, a foil face, and an intermediate layer of cement, substantially as specified.

4. As an article of manufacture, a fabric for forming polishing-laps, which consists of a flexible backing, a corrugated foil face, and an intermediate layer of cement, substantially as specified.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE E. BROVN.

Vitncsses: Y

I-I. R. CLIsn, C. E. CRANE. 

